Integrated circuits, such as memory devices, are continually being reduced in size. As a result, higher numbers of electronic components are present in a given area of integrated circuitry, resulting in a need for smaller pitched interconnect structures for physically and/or electrically connecting the integrated circuitry, e.g., to external support structures and external circuitry.
For example, internal lines, e.g., control signal lines, address signal lines, DQ signal lines, interconnect lines, etc., within memory devices, such as a dynamic random access memory (DRAM), flash memory, static random access memory (SRAM), ferroelectric (FE) memory, etc., are becoming smaller. In some applications, these internal lines may be connected to conductive pads or pins on a printed circuit board that forms a portion of a memory package.
Pitch is a quantity commonly used when addressing the spacing between neighboring features, such as adjacent conductive lines, in an integrated circuit. For example, pitch may be defined as the center-to-center distance between two adjacent lines. Lines are typically defined by spaces between adjacent lines, where the spaces may be filled by a material, such as a dielectric. As a result, pitch can be viewed as the sum of the width of a line and of the width of the space on one side of the line, separating that line from an adjacent line. However, due to factors such as optics and light or radiation wavelength, photolithography techniques each have a minimum pitch below which a particular photolithographic technique cannot reliably form lines. Thus, the minimum pitch of a photolithographic technique is an obstacle to continued line size reduction.
“Pitch multiplication,” such as “pitch doubling,” is commonly used for extending the capabilities of photolithographic techniques beyond their minimum pitch. The pitch is actually reduced by a certain factor during “pitch multiplication.” For example, the pitch is halved during “pitch doubling.”
Contacts are sometimes used to electrically and/or physically connect lines, such as pitch-multiplied conductive lines, to other lines (e.g., at other vertical levels) within the integrated circuit. For example, the other lines may connect integrated circuitry to external support structures and external circuitry.
The contacts can be larger than the pitch-multiplied conductive lines and the pitch, making it difficult to connect a contact to a pitch-multiplied conductive line without contacting an adjacent pitch-multiplied conductive line with the contact, thereby shorting the adjacent lines together. Therefore, a pitch-multiplied conductive line may be enlarged in the region where it is to be connected to a contact, e.g., so that the contact may be entirely enclosed within the region. However, the dielectric between adjacent pitch-multiplied conductive lines can break down where it wraps around the enlarged region, causing an electrical short between the adjacent pitch-multiplied conductive lines.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternatives for connecting contacts to conductive lines.